I created a backup but now I cannot see it
Backup is associated with one Google Account (email). Please make sure that you are using the same Google Account on your new phone. The current account is displayed at the bottom of Backup & Restore screen.
If you want to find out which Google Account (email) contains your previous backups, please go to https://drive.google.com/, click Settings icon (in the right corner) then Manage Apps. You should see
If you have multiple Google Accounts you can switch between the individual accounts and check which of your accounts contain your Google Drive backups.